How much does a web application cost? From internal tool to platform

For many companies, a web application is the most direct way to replace Excel lists, paper forms and endless e-mail threads with one continuous digital process. It runs in the browser, needs no installation and is available in its latest version on every device. But how much does it cost to have a web application developed? This guide gives realistic price ranges, explains the main cost drivers and shows which obligations and running costs you should plan for. As of September 2026.

Price ranges for typical web applications

According to our cost model, which also underpins the project cost calculator and is benchmarked against published market prices of German agencies, a simple internal tool costs about €16,500–29,000. A customer portal with ERP integration comes to about €45,000–81,000, a platform or SaaS solution to about €115,000–210,000. All prices are net and include project management and quality assurance.

The three tiers reflect different demands. An internal tool has a small number of known users and usually replaces one clearly defined process. A customer portal opens company data to external users and therefore needs clean permission management and a reliable connection to the ERP system. A platform, finally, is a product in its own right, with sign-up, billing, many user groups and high availability requirements.

What determines the effort

The biggest cost driver is scope: how many screens, processes and special cases does the application have to cover? Close behind comes the question of who uses it. A handful of employees with identical permissions is quickly catered for. Public sign-up, single sign-on with the company account or finely graded roles for customers, partners and back-office staff require additional logic and considerably more testing.

Data is another item. Hardly any web application stands on its own; it reads orders from the ERP, creates contacts in the CRM or passes invoices to accounting. Every interface takes effort, especially if the other side does not offer a modern API. For reference: according to our cost model, an interface from the ERP to an online shop comes to about €4,500–8,500, a near real-time connection between ERP, shop and CRM to about €9,500–17,500.

Finally, the user interface also shapes the price. Forms and lists are standard. Interactive planning views, drag and drop or dashboards with many filters take more development time, and a custom design system is more work than a plain, functional layout. If designs already exist, that saves time.

An example: a wholesaler's customer portal

A typical project shows how these factors play out. Take a wholesaler of plumbing supplies planning a portal for around 800 business customers. Customers should be able to log in, view orders and delivery status, download invoices and file complaints with photos. The data comes from the ERP system.

A portal like this sits in the middle tier, at about €45,000–81,000. Where exactly it lands within that range depends on the details. Are read-only views of orders and invoices enough, or should customers also be able to order directly? Does the ERP offer a modern interface, or does the data have to be synchronised in a roundabout way? Does every customer need several logins with different permissions, for example for purchasing and accounting? And should a complaint with photos automatically open a case for the back office? Each of these questions shifts the effort noticeably. The more of them are settled up front, the tighter the estimate becomes.

Legal requirements as a cost factor

Web applications almost always process personal data. Article 25 of the GDPR requires "data protection by design": appropriate technical and organisational measures must be implemented as early as the time of determining the means for processing, not only once the system is running. Roles, retention periods, logging and encryption therefore belong in the concept from day one. Added later, they cost more.

For applications aimed at consumers, accessibility comes on top. Germany's Accessibility Strengthening Act (Barrierefreiheitsstärkungsgesetz, BFSG), which implements the European Accessibility Act, applies to services provided to consumers after June 28, 2025, including "services in electronic commerce"^*. Exempt are microenterprises with fewer than ten employees and an annual turnover or balance sheet total of no more than two million euros that provide services. A purely B2B portal is not covered. But if you serve consumers, you should plan accessibility into the design and testing; that is considerably cheaper than retrofitting it later.

Operations and further development

After go-live, running costs arise. The server itself is rarely the big item: according to Hetzner's price list, cloud servers with shared vCPUs start at €6.49 per month net. For a business-critical application, you need to add backups, monitoring, a test environment and, above all, maintenance.

Every framework has a life cycle. With the widely used framework Ruby on Rails, for example, minor releases receive security fixes "for two years after the first release in its series". After that, a version upgrade is due. Planning such upgrades regularly avoids a costly modernisation backlog. Our guide Ongoing software costs explains how to budget for maintenance, hosting and support.

Web application, app or off-the-shelf software?

A web application is often the most economical route, because one code base reaches every device and no app store approvals are needed. As a progressive web app, it can even be added to the home screen. A native app pays off when the camera, offline use or push notifications are central; our guide How much does an app cost? shows what that costs. And sometimes an off-the-shelf product with a good interface is the better answer. Our article Off-the-shelf vs. custom software describes how to weigh it up.

Conclusion: start small, build properly

The cost of a web application follows its users, its data and its processes. If you start with the core, clarify interfaces and legal requirements early and plan operations from the outset, you get an application that grows with your company for years instead of turning into a legacy system after a short time.

At 4eB, we develop web applications with Ruby on Rails, PostgreSQL and React, among others – from internal tools to platforms. We have been running and developing the ClicClic event photo platform for PicturePartners since 2015, for example. The project cost calculator gives you an initial cost range for your project; you will receive a binding quote after a short conversation with us.

Sources

• Art. 25 GDPR (Data protection by design and by default), accessed September 29, 2026 (in German)
• Barrierefreiheitsstärkungsgesetz: § 1 BFSG (scope), § 2 BFSG (definitions) and § 3 BFSG (accessibility requirements), accessed September 29, 2026 (in German)
• Hetzner: Cloud Server, price list, accessed September 29, 2026
• Ruby on Rails: Maintenance Policy, accessed September 29, 2026

* Our translation of a quote from a German-language source.